After you clear a landing pad from Jump-Pack Brutes and clear the area for the Pelican, go through the door and you will start going up stairs that lead to a power up cache. One of these sets of stairs will have the top two steps missing and there will be just blackness there. Stand there and you will be completely black.

Note: This glitch has also been seen in some multiplayer maps, such as Guardian and Avalanche.
Another Note: An alternate version of this glitch for Halo 2 can be seen on the page Golden Touch.